src/java.desktop/share/classes/java/awt/Font.java

*** 764,773 ****
--- 764,816 ----
          this.nonIdentityTx = values.anyNonDefault(EXTRA_MASK);
          this.hasLayoutAttributes =  values.anyNonDefault(LAYOUT_MASK);
      }
  
      /**
+      * Return true if any part of the specified text is from a
+      * complex script for which the implementation will need to invoke
+      * layout processing in order to render correctly when using
+      * {@link Graphics#drawString(String,int,int) drawString(String,int,int)}
+      * and other text rendering methods. Measurement of the text
+      * may similarly need the same extra processing.
+      * The {@code start} and {@code end} indices are provided so that
+      * the application can request only a subset of the text be considered.
+      * The last char index examined is at {@code "end-1"},
+      * i.e a request to examine the entire array would be
+      * <pre>
+      * {@code Font.textRequiresLayout(chars, 0, chars.length);}
+      * </pre>
+      * An application may find this information helpful in
+      * performance sensitive code.
+      * <p>
+      * Note that even if this method returns {@code false}, layout processing
+      * may still be invoked when used with any {@code Font}
+      * for which {@link #hasLayoutAttributes()} returns {@code true},
+      * so that method will need to be consulted for the specific font,
+      * in order to obtain an answer which accounts for such font attributes.
+      *
+      * @param chars the text.
+      * @param start the index of the first char to examine.
+      * @param end the ending index, exclusive.
+      * @return true if the specified text will need special layout.
+      * @throws IllegalArgumentException if {@code chars} is null.
+      * @throws ArrayIndexOutOfBoundsException if {@code start} is negative or
+      * {@code end} is greater than the length of the {@code chars} array.
+      * @since 9
+      */
+     public static boolean textRequiresLayout(char[] chars,
+                                              int start, int end) {
+         if (chars == null) {
+            throw new IllegalArgumentException("null char array");
+         }
+         if (start < 0 || end > chars.length) {
+             throw new ArrayIndexOutOfBoundsException("start < 0 or end > len");
+         }
+         return FontUtilities.isComplexScript(chars, start, end);
+     }
+ 
+     /**
       * Returns a {@code Font} appropriate to the attributes.
       * If {@code attributes} contains a {@code FONT} attribute
       * with a valid {@code Font} as its value, it will be
       * merged with any remaining attributes.  See
       * {@link java.awt.font.TextAttribute#FONT} for more